This application is a competitive renewal of "A Domestic Bolivian Squirrel Monkey Breeding Resource" which has been funded continuously at the University of South Alabama Primate Research Laboratory since 1980. The overall objective of the project has been to implement a multidisciplinary research and breeding program aimed at optimizing captive reproduction of the squirrel monkey. The project has evolved over the years into the only breeding resource of squirrel monkeys in the United States and has led to the development of a research and management team with concentrated expertise on the reproduction, care and use, and basic biology of the squirrel monkey. It is for this reason that we have changed the title of the project to "A Squirrel Monkey Breeding and Research Resource". The project provides a national resource meeting biomedical research needs in three ways. First, it provides a unique resource of laboratory born squirrel monkeys of known medical history, age, and pedigree. Second, the resource's research program continues to add new information about the basic biology of squirrel monkeys with particular emphasis on the reproductive biology and colony management. And third, the resource will develop and make available squirrel monkey specific antibody and assay methods for selected peptide hormones. These will be made available to others who wish to study these hormones in squirrel monkeys. The increasing scarcity of squirrel monkeys and universally experienced difficulties associated with captive reproduction, necessitate continued research into the reproductive biology, social behavior in captivity, veterinary medical care, genetics, and management of this important genus. These disciplines have been integrated into a multidisciplinary program designed to meet the overall goals of the breeding resource. In this way, a continuing supply of squirrel monkeys can be provided for biomedical research while expanding our basic understanding of squirrel monkey biology. The results of studies within the resource are applied to the management of the colony. Over the past five years, the breeding colony has improved in overall reproductive performance and has provided more than 120 squirrel monkeys for research at other institutions. This balance between research and breeding colony management provides an appropriate environment for providing a continuing supply of these scarce animals and optimizing efficient use of the limited numbers available.